Plate Tectonics Study Guide
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I.
Earth’s interior
A. Earth’s interior has 3 main layers
1.Crust
2.Mantle
3.Core
B. The mantle is made up of 2 layers (List and identify information about
each)
1.Lithosphere- The Crust that is being moved .
2.Asthenosphere-The Asthenosphere is where Convection Currents
happen.
C. There are 2 parts that make up Earth’s Core (List and identify information
about each)
1.Inner Core- A solid part of the Earth’s core, made up of iron.
2.Outer Core- A liquid layer of the Earth’s core, made up of iron and
nickel, by spinning around the inner core, it creates the magnetic
field.
II.
D. As depth beneath Earth’s surface increases, Heat and Pressure both
increase.
E. Geologists observe earth’s interior by studying Seismic Waves which are
an example of indirect evidence.
F. Geologists observe earth’s interior by studying rocks, which are an
example of direct evidence.
Convection Currents and the Mantle
A. Heat can be transferred in three ways
1. Radiation
2. Conduction
3. Convection
B. Differences in temperature and density within a fluid cause convection
currents in the mantle.
When things get cold they sink, when they get hot they rise.
III.
Drifting continents
A. Alfred Wegner developed the idea that the continents were once joined
together as a super-continent called Pangea and have since drifted apart.
B. Most scientists rejected Wegener’s theory because he could not identify a
force that could move the continents.
C. Continental drift occurs because of seafloor spreading.
IV.
V.
Sea Floor Spreading
In sea floor spreading, molten ma forms new rock along the midA. Ocean ridges, which was mapped by Sonar technology was used to map
the ocean floor
B. In Subduction , the ocean floor sinks back to the mantle beneath the deep
ocean trenches.
C. Molten material erupts at the mid-ocean ridge during sea floor spreading.
D. The age of rock far away from the mid-ocean ridge was
determined by drill samples of the rocks
E. Mid- ocean ridges are located in all/every ocean(s)
F. The youngest rocks on the ocean floor are located at Middle of the mid ocean
ridge
VI.
The theory of plate tectonics
A. Plates slip past each other at transform boundaries, move apart at
divergent boundaries and come together at convergent boundaries; the
movement is caused by convection currents in the asthenosphere.
B. Subduction is where one plate goes under another plate
C. Old ocean crust is more dense because it is colder.
D. The plates move because of convection currents in the asthenosphere.
E. Mountains result from two pieces of continental crust colliding
F. The place where two plates come together is a convergent plate boundary
G. When continental plates pull apart a rift valley forms.
H. Earthquakes produce seismic waves that travel through the Earth, and
geologists study these to “see” into the Earth
I. Where two of Earth’s plates slip past each other moving in opposite
directions is called a transform boundary.
J. Rock that makes up oceanic crust basalt.
Words to Know for Plate Tectonics
Continental Drift
Pangaea
Seafloor Spreading
Plate Tectonics
Convection Current
Divergent Boundaries
Convergent Boundaries
Transform Boundaries
Mid-Ocean Ridges
Subduction
Rifting
Magma
Volcanoes
Earthquakes
Fossils